Method of forming radiator elements



April 8, 1930. J. KARMAzlN METHOD OF FORMING RADIATOR ELEMENTS Filed May 7, 1925 2 Sheets-Sheet l INVENTOR ZlN ' ATTORNEY April 8, 1930- J. KARMAzlN 1,753,295

METHOD 0F FORMING RADIATOR ELEMENTS Filed May '7, 1925 2 Sheets-Sheet 2 INVENTOR f to back of the radiator, in lieu of one revolu- Y Patead Apr. s, 1930 UNITED lsT-A JOHN: KARMAZIN, OF DETROIT, MICHIGAN Jsm'rironA or Femme appiimion, mea nay 7,

This invention relates ,to radiators suitable for use in water cooled lnternalv combustion engines and other heat transfer apparatus,

suclr` as disclosed in my copending application/Serial No. 641,850, filed May 28,1923.

Radiators of the type referred to are comprised of a stack of superposed -iin elements, each comprising a flat portion with integral tapered tubular projections extend- `ing from the' iin, the projections ofone elementv being adapted to telescope into the projections of the adjacent element whereby continuous water tubes are jformed through the parallel fin members.

The machines used for formin the tubular projectionfrom the fin, in a series of steps and punching out the'bottoms thereof, which is adapted to receive a strip of metal approximately as wide as the thickness ofthe radiator from front to back, and

to form from that `strip tapering tubular projections, the formed strip being subsequently cut off in predetermined lengths and the cut elements stacked upon one another with the tubes in telescoping relation to form the radiator. Such machine is illustrated in .my copending application above referred to.

Heretofore, byl feeding a narrow strip 3o lengthwise into t e machine, it was necessary 4that the machine make some/ twenty-eight revolutions for each radiator strip or ele- -ment, or one revolution for every row of tubes from 'side to side of the radiator.

Oneobject `of my present invention is to provide a machine and methodof formin radiator elements of the type describe which will diminish the time Irequired to form a radiator, such machine comprising a radiator element forming device which will receive a strip of metal as wide as the radiator is wide and form tubular projections therefrom to form the complete element, in one, two, three or more revolutions, or one revolution for each row of tubes from front tion foreach row o f tubes from side to side of the radiator. Another object of my invention is to provide almachine comprising a radiator. ele.-

these-v radiator elements include a die for orming mmrn'ron ELEMENTS 192.5. serial No. 28,538;

ment forming device which will receive a strip of metal as wide as the radiator is wide and form a large number of tubular projections across the width of the sheet without materially thinning or weakening the sheet.

A further object of the invention is to provide a machine-inwhich the number of rows of tubes from front to back of the radiator being made may be changed at .will by merely cutting off different widths of the strip as it emerges from the machine 'to form radiators of different widths.

Another object of the invention is to provide amachine for manufacturing radiator elements in which the elements formed `may '65 be trimmed at the ends in lieu of along the sides as in the present practice whereby a great deal of material ordinarily wasted may be saved. A

A further object of my invention is to pro- '70 Vide a method of manufacturing radiators accordingI to which a strip of sheet metal as wide as the radiator is deformed to provide rows of transverse tubes integral with the sheet and cut` into sections, such sections be- 15- ing stacked with the tubes thereofin telescoping relation and compacted into a radiator.

A further object of my invention is to 'provide a method of manufacturing a radiator by forming radiator elements having tubular projections on and ofa sheet of metal as wide as the radiator by starting the operations necessary to form the tubular projections for the central row-in the center of the sheet, and 35' starting the operations for forming the projections in successive adjacent rows in yrows diverging forwardly'from the center of the sheet, thereby permitting the reduction in the width of the sheet 'caused by the initial90 tubepforming steps -without rupturing or straining the metal in the plane of the sheet.

Other objects and advantages of the invention will appear as the description thereof proceeds. A 95 Inv the drawings, which illustrate av preerred form of einbodiinent of the invention f Fig. 1 is a diagrammatic plan view ofthe Y forming dies; v 100 Fig. 2 is a Sectional elevation of the forming dies and feeding rolls taken partially on the line -2-2 of Fig. 1;

Fig. 3 is a top view of a portion of the formed sheet with the tube projections formed thereon; and

ameter to receive all of the material required to form the tube and the rest gradually decreasing in diameter and increasing in depth until the desired tube has been formed. Several rows of tubes may be formed 4at once in this manner without materially weakening or thinning the sheet, as the material for the first 'depression can be 4drawn in from the edges, but if an attempt is made to start a large number of tubes in one row at the same time,` seriousv strains might develop across the sheet, due to the tendency to draw a portion of the metal of the sheet into the initial depression, which would tend' to rupture the sheet. I have eliminated this tendency in my present invention by forming the first depression in the center of the sheet, and the succeeding depressions simultaneously on each side of 'the' center in rows diverging from the center. Thus, as each depression is formed, the metal is free to be drawn into it4 from the side of the sheet, as indicated by the wrinkled edge 12of the sheet 12, permitting sufficient metal to be displaced into'the first depression of each row to form the tubes of that row without materially thinning the walls of the tubes from the thickness of the sheet and without causing ruptures in the plane of the sheet. Any press of suitable size such as that described in my co-pending application, may be used for forming the radiator elements according to my present invention.

The die of my present invention consists of a base 10, into which are set therows of'successive shaping dies 11 necessary to complete the formation of the tubular' projections. The dies 11 are arranged in a V-shaped row. as indicated in Fig. 1, of the drawings so that as the sheet of material 12 is fed through the dies, from top to bottom in Fig. 1, the center row of the dies A makes the first impressionl on the sheet and successively thereafter with each revolution of the machine, one row of dies on each side begins to function untily a tubular projection is formed by each row of dies at each operation ofthe press. Cutter guides 13 at the rear of the die attached to the upper die and reciprocating -in openings 13a in the lower die together with the cutters 14 at the front guide the sheet'through the die. The cutters 13 and 14 also trim the edges of the sheet and determine the spacing of the tubular projections on the sheet as itpasses therethrough, as will be described. l. f

Downwardly extending forming punches are carried by the upper male die member 15, such punches cooperating with the female dies carried on the base 10', all as more specifically described in my copending application above referred to. Each row of punching dies in the longitudinal directio'ii of the machine a's shown in Fig:l 2, comprises a flat faced die 16 which smoothes or iattens the wrinkles out of the sheet which are formedv in making the first depression for the preceding tube before the first depression 162l is made and a last punch 16j which punches out the bottom of the depression forming the tubular projections therefrom.

The intermediate punches 16b, 16, 16d, 16", 16f, 16g and 16h, and the corresponding lower matrices successively reshape the metal which is displaced from the plane of the sheet 12` by the rst punch 16a from a wide shallow depression into a narrower and deeper depression from which the bottom is removed by the punch 16j to form a tube.

Followin the forming dies is a punch 18, which punc es a hole 19 in the lateral plane of the plate 12 for the purpose of/lightening the material and increasing the circulation of air over the tubes. These holes have been 'indicated at 19 in Fig. 3 at either'end of the ure.

The sheet 12 is preferably'drawn forwardl through the dies 11 and 15 by means of a pair of constantly driven rollers 20 and 21 which frictionally engage the upper and lower surface of the sheet 12 with sufficient pressure to draw the sheet forward when the dies, punches 16 and trimmers 13 and 14 are ele vated but slip on the surface of the sheet when the sheet is held stationary by the forward edges of the recesses 13 and 14a for the trimmers 13 and `14. The roller 21 is provided with grooves 21a to accommodate the projections on the sheet 12.

The various punches 16, 16h, 16, etc., and the corresponding matrices 11 are spaced an equal distance, so that the space from center to center of each depressiOn of the sheet is the same, and to assure that the strip 12 will be moved forward the distance of one space atV each'elevation of the dies. The trimming knives 13 and 14 in the longitudinal direction of the sheet are of the same width as the spacing of the dies, and thefforward edges of the recesses 13a and 14a for the knives 13 and 14 project inwardly the thickness of the knives, so that each depression of the upperv die member 15 and knives 13 and 14 trims from the edge of the .sheet rectangular portions of about the size ofthe knife, .and leaves shouliso ders 12a and 12b on lthe sheet, which, when strip of material into the machine to give the A proper spacing as the strip is fed in.

Every revolution of the machine produces one row of tubes across the width of the sheet 12, and it will be noted that if the elements are cut 0E after two rows of tubes have been formed, as indicated by the line 17-17 in Fig. 3, the element will contain two rows, and if the element is cut 0E after three rows have been formed, the element will contain three rows, and so on, so that it is possible to obtain any desired number of rows of tubes by lmerely cutting oi the desired number from the finished sheet.

1t is possible, therefore, by my invention, to form radiators with one, two, three, or more rows of tubes from the same die, and by a fewer number of steps, whereas under the prior practice, a separate die was necessary for each dierent Width of radiator and a greater Anumber of steps necessary to form each element.

My invention is not to be considered as limited to the precise construction and method of operation hereinbefore described, but isl to be construedas covering all equivalent machinesand processes coming within the scope of the appended claims.

I claim:

l. The method of making a radiator comprising the step of forming tubular projections from and integral with a metal strip whose width is approximately equal to the length of a finished element by forming successive depressions at each side of the center in diverging directions and cutting said strip into radiator elements of the same width as the thickness of the radiator to be formed.

2. The method of making a radiator which comprises forming long rows of tubular projections from a flat metal strip transversely of the length of said strip by" forming an initial depression in the center of the strip and forming successive depressions at each side of the center in a forwardly diverging direction toward the sides of the strip.

3. The method of making a radiator which comprises the step of forming long rows of tubular projections from and integral with a metal strip and transversely of the length.

of said strip by forming said projections successively starting at the center a'nd Working toward the sides so that not more than one projection is formed at each side of the center of the strip at the same time.

ldi'ator elements.

wide strip of sheet material without reducing the thickness of said sheet by successively forming a V-shape plan of apertures in the length of the sheet, severing a radiator element transversely from said formed strip, and superposing elements of the strip thus formed with the projections of adjacent elements in mutually engaging relation.

5. The method of making a radiatorcomprising the steps of successively forming long' rows of shallow depressions in and transversely of a wide strip of sheet material, said rows being a V-shape plan having not more thantwo depressions transverse of the strip, reforming said depressions into recesses of a desired size and depth without materially altering the thickness of the material, punching the bottoms from said recesses to form tubes and superposing sections of the strip thus formed with the tubes of adjacent sections in engaging relation. l

6. The method of making a radiator comprising the step of forming long rows ofshallow depressions in a wide strip of sheet material, such depressions being formed successively, thereby successively reducing the width of the strip, simultaneously forming a single depression in the center of said strip,

reforming said depressions into recesses of the desired shape and size without further reducing the width of said strip, and punching the bottom from said recesses to form tubes and superposing sections of the strip thus formed.

7. The method of making a radiator which comprises forming initial depressions in the center of a wide sheet of material, and simultaneously thereafter forming additional initial depressions progressively at each side of said central depressions and reforming said previously formed initial depressions without disturbing the sheet adjacent thereto.

8. The method of making radiator elements of the type described, which comprises producing a shallow depression of predetermined outline in the center of a wide strip of producing a similar depression forwardly o and at either side of the first depression whereby the strip is narrowed agam, producing successively other similar depressions forwardly ofyand at successively greater distances from thevcenter whereby the sheet is narrowed successively and thereafter in'- creasing the depth of the depressions and simultaneously decreasing the1r outline and severing transversely of the sheet to form ra- In testimony whereof I have axed my signature to this specication.

JOHN KARMAZIN.

4. The method of making a radiator which f comprises the steps of forming -long rows of tubular projections on and transversely Aof a.

-sheet met-al whereby theJstrip is narrowed 

